Rock sculpturing by extreme meltwater flow in western Greenland?

摘要

The genesis of small dimensional rock sculptures such as cavettos, hairpin scours, komma marks, flutes, etc. is still under debate. Fluvial processes certainly play a role, but it is an open question whether the sculptures have been formed sub-glacial with hydrostatic pressure or sub-aerial during extreme melt water discharge. This paper described so far known and unknown small dimensional forms on very old and hard crystalline rocks in West Greenland near Kangerlussuaq. These forms appear in an area free of ice since ca. 8,000 yrs, 15-20 kin from the inland ice margin and are older than deep fissures in the rock on which they appear. The fissures presumably result from permafrost decay, which provides another possibility for mutual age estimation.